Iran hanged on Saturday six convicted drug traffickers in a prison in Karaj, west of Teheran, the official IRNA news agency reported.The report identified the men as Arsalan Asadi, Mohammad Ali Fakhri, Abbas Geravand, Rahman Biabani, Saeed Mikaili and Parviz Taghizadeh.The hangings bring to at least 56 the number of people executed in Iran so far this year, according to an AFP count based on news reports. Last year, at least 270 people were hanged. Teheran says the death penalty is essential to maintain public security and applied only after exhaustive judicial proceedings. Murder, rape, armed robbery, drug trafficking and adultery are all punishable by death in Iran.